Method of and apparatus for assorting wood-pulp chips



(No Model.)

v R. S.TALBO-T. METHOD OF AND APPARATUS FOR ASSORTING WOOD'PULP CHIPS.-No. 556,111.

JPatented. Mar. 10,-1896 l N YENTElR j /$.JM

WTNESSESL ANDREW B.GRANAMv FHOT0-UTHU.WASHINGTDN DC UNITED STATES PATENTOFFICE.

REGINALD S. TALBOT, OF LINCOLN, MAINE, ASSIGNOR TO THE NElV ENG- LANDSULPHITE DIGESTER COMPANY, OF BOSTON, MASSACHUSETTS.

METHOD OF AND APPARATUS FOR ASSORTING WOOD-PULP CHIPS.

SPECIFICATION forming part of Letters Patent No. 556,1 11, dated March10, 1896.

Application filed June 3,1895. Serial No, 551,499. (No model.)

To all whom it may concern.-

Be it known that I, REGINALD S. TALBOT, of Lincoln, in the county ofPenobscot and State of Maine, have invented certain new and usefulImprovements in Apparatus for Assorting Wood-Pulp Chips, of which thefollowing is a specification.

This invention relates to the preparation of chips used in themanufacture of wood pulp, and it has for its object to enable such chipsto be effectively and economically assorted by separating the chips madewholly or principally from the knots and knotty portions of the woodfrom the chips made from the clear portions.

The knotty portions of spruce and other woods used in the manufacture ofpulp are very dense and tough and contain so much resinous matter thatthey cannot be satisfactorily cooked of reduced to pulp. Moreover, theyare dark in color and contrast strongly with the color of the clear-Woodpulp. For these reasons the presence of knot-wood in a charge of chipsis a serious disadvantage. Attempts have been made to eliminate theknotwood by cutting or boringout the knots prior to the reduction of thelog to chips and by picking out the knot-wood chips by hand while thechips are spread out and being carried bya conveyer. All the methodsheretofore used are expensive and unsatisfactory and fail to perfectlyaccomplish the end desired.

My invention is based upon the discovery that when a mass of chips isdeposited upon the surface of a body of liquid and broken up orscattered, and at the same time forcibly submerged, so that the chipswill be separated or freed from each other below the surface of theliquid, the knot-Wood chips becoming partially saturated by the liquidwill sink, their specific gravity being greater than that of the liquid,particularly after their surfaces have been exposed to contacttherewith. The clearwood chips, on the other hand, are not affected bythis surface saturation and therefore rise to the surface of the liquidowing to the difference between their specific gravity and that of theliquid.

My invention therefore consists in a chipassorting apparatus comprisinga tank, a body of liquid therein, a striker or agitator subdividing thesurface of the liquid into a chipreceiving area and a chip-deliveringarea, said agitator being constructed and arranged so that when inoperation it forcibly submerges and scatters the chips which aresupplied to the receiving-area, and separating the chips from eachother, causing their surface saturation and therefore the settling orsinking of the kn ot-wood chips and the rising of the clearwood chips,the latter entering the delivering area of the body of liquid from whichthey are removed by a conveyer entering said delivering-area, saidconveyer being included as a part of my improved apparatus.

Of the accompanying drawings, forming a part of this specification,Figure 1 represents a partial side elevation and partial verticalsection of an apparatus embodying my improvement. Fig. 2 represents atop plan View of the same.

The same letters of reference indicate the same parts in both thefigures.

In the drawings, (1 represents a tank containing a body of liquid.

19 represents an agitator or striker, which, as here shown, consists ofa horizontal shaft extending across thetop of the tank and provided witha series of radial blades rigidly 8o affiXed to the shaft, means beingprovided for rotating the shaft, the blades of which are formed to enterthe body of Water and positively press down and submerge any floatingchips with which they may come in contact while moving downwardly. Theagitator or striker 19 extends across the tank, as shown in Fig. 5, andis located between the ends thereof, so that it subdivides the surfaceof the body of liquid into a receiving-area, which 0 is located below a'supply spout or chute c and a delivering-area into which extends aconveyor e, hereinafter referred to.

While my invention is not limited to the particular form of agitator orstriker here 5 shown, it is important that said striker possess thefollowing characteristics, namely: First, it must be constructed so thatit will strike and forcibly scatter chips floating upon thereceiving-area, effectually separating said chips from each other andsubmerging them in the body of liquid; second, it must obstruet only acomparatively narrow line or section of the surface of the liquid, sothat the clear-wood chips can rise quickly to the delivering-area of thebody of liquid without beingheld below the surface of the liquid longenough to become soaked to such an extent as to cause them to sink, aresult which might take place if they were submerged for anyconsiderable length of time. These results are secured by theconstruction here shown, the rotary agitator, composed of the shaft andthe radial arms or beaters rigidly affixed thereto, obstructing but asmall portion of the surface of the liquid and being separated from theconveyer e by an area of considerable ex tent.

The conveyer e is here shown as an endless band, mounted upon rolls ee", the former being below the surface of the liquid, while the latteris above said surface. The conveyer is inclined and is driven in thedirection indicated by the arrow in Fig. l by power applied to one ofthe rolls.

The rotation of the agitator 1) not only scatters and submerges thechips, as above stated, but also moves the liquid at and near thesurface in the direction indicated by the arrow 50 in Fig. 1, the liquidbeing thus caused to convey the clear-wood chips to the conveyer e.

(1 represents a second conveyer, located below the conveyer e andsupported by rolls (1 (1- the lower end of the conveyer (i extendinginto the tank farther than the lower end of the conveycre, so that theconveyer d is arranged under the chip-receivin g area of the body ofliquid and receives the heavier chips and other matters that fall in thebody of liquid. The matter deposited upon the conveyer d is elevated bythe latter and discharged from the tank, the said conveyer beingimpelled in the direction indicated by the arrow marked thereon in Fig.1.

g represents a pump, which is connected by a suction-pipe g with acompartment in the lower portion of the tank, said compartment beingcomposed of perforated pieces a a The pump is connected by adelivery-pipe g with a forcbay g at the upper portion of the tank, thearrangement being such that the operation of the pump causes acirculation of water in the tank,whereby the liquid is caused to movethe floating chips toward the conveyer e. The pump is used when it isdesirable to economize the use of water, but when such economy is not anobject the pump may be dispensed with and a stream of water may beallowed to enter at one end of the tank and escape at the other end.

The operation is as follows: The chips are supplied to thereceiving-area of the body of liquid through the spout c and areattacked by the agitator or striker and separated from each other andforcibly submerged, the chips being thus superficially saturated, sothat the sinking of the knot-wood chips is insured, the clear-wood chipsrising into the deliveringarca of the body of liquid and being conveyedby the movement of the liquid to the conveyor 6, by which they areremoved from the tank.

It will be seen that my invention provides for the economical andefficient separation from the clear-wood chips of not only knotwood, butalso pieces of bark and what is known as sap-rotten wood, these partswhen saturated with water being of greater specific gravity than water,so that they readily sink.

The thorough removal of knot-wood, bark, and sap-rotten wood fromwood-pul p chips is a very great advantage in the art ofmanufacturingwood pulp, since it prevents the discoloration andcontamination of the pulp by elements which are in every respectobjectionable. The ordinary knot-wood is objectionable,because whenreduced it leaves darkcolored sheaves and strings in the pulp, while thebark and rotten wood when reduced arc disintegrated into a fine powderand discolor the portions of the pulp into which they are incorporated.

It is obvious that my invention may be practiced by the use of anysuitable liquid for separating the different grades of chips, the use ofpure water not being essential--that is to say, I may use a bisulphitcsolution, such as that employed in cooking the pulp, or any othersuitable liquid which will permit the ready separation of the diifercntgrades of chips from each other.

The knot-wood chips constitute a by-product which may be utilized asfuel, the said chips being rich in resinous matter.

I claim- A chip-assoriing apparatus comprising a tank, a body of liquidtherein, a rotary agitator or striker subdividing the surface of theliquid into a chip-receiving and a chip-delivering area, said agitatorforcibly submergin g chips floating on the receiving-area and permittingthe submerged chips to rise into the delivering-area, and a conveyerarranged to remove floating chips from said deliveringarea, the agitatorand conveyor being separated by a space sufficient to permit the lighterchips to rise without interfering with the settling of the heavierchips.

I11 testimony whereof I have signed my name to this specification, inthe presence of two subscribing witnesses, this 25th day of May, A. D.1895.

REGINALD S. TALBOT.

\Vitnesses:

FRANK R. LINTON, GEORGE F. ROWE.

